Some materials for pipeline welding have maximum temperature limits which should not be exceeded in order to achieve desired material properties in the welded joint and the heat affected zone (HAZ) of the pipe adjacent to the weld. Current welding systems fail to prevent overheating of the HAZ and regularly allow maximum temperature limits to be exceeded.
The heat from the welding process often overheats the pipe being welded to a temperature above the maximum temperature limit for the pipe. Such overheating can lead to weld failure, pipe failure, or can cause welding to be stopped until the pipe cools to a temperature less than the maximum temperature limit sufficient to allow welding to resume. In other cases, welds and pipes and/or pipe segments which are noncompliant to specifications as a result of failure to control the temperature of the HAZ during welding have to be removed and the pipes re-welded.